Building structure having facing slabs and removable securing means therefor



N 1967 w. K. SMITH, JR.. ETAL 3,350,830

BUILDING STRUCTURE HAVI NG FACING SLABS AND REMOVABLE SECURING MEANSTHEREFOR Filed May 5. 1965 3 Sheets-Sheet 1 INVENTORS WALTER K.SMlTH,JR.' CHARLES T. PHILLIPS ATTORNEY 5 Nov. 7, 1967 w. K. SMITH, JR..ETAL 3,350,830 BUILDING STRUCTURE HAVING FACING SLABS AND REMOVABLESECURING MEANS THEREFOR Filed May 5, 1965 3 Sheets-Sheet 2 38 2Q /////7i 4% 34 I v I, /,A// 64 4 5o 4 i as 38 M 62 mnmnmm 24 l .q r3 7 i' \leFIG 4 INVENTORS WALTER K. SMiITl-LJR. CHARLES T. PHILLIPS BY $56M QATTORNEYS Nov. 7, 1967 w. K. SMITH, JR. ETAL 3,350,830 BUILDINGSTRUCTURE HAVING FACING SLABS AND REMOVABLE SECURING MEANS THEREFORFiled May 5, 1965 3 Sheets-Sheet 3 I NVENTOR 5 WALTER K. SMITH,JR.CHARLES T. PHILLIPS BY Jiwg J y ATTORNEYS United States Patent 3,350,830BUILDING STRUCTURE HAVING FACING SLABS AND RER EGVABLE SECURING MEANSTHERE- FOR Walter H. Smith, Jr., 787 Ocean Shore Blvd Ormond Beach, Fla.32074, and Charles T. Phillips, 1347 Continental Drive, Daytona Beach,Fla. 32017 Filed May 5, 1965, Ser. No. 453,272 10 (Jlaims. (Cl. 52--509)This invention relates to a building structure having facing slabsremovably secured thereto, and to the means for effecting such securing.While applicable to many different types of building structures overwhich facing slabs are to be used, the invention is particularly usefulin connection with burial crypts, mausoleums, and the like. These areusually constructed of precast concrete and faced with rectangular slabsof marble, or other stone, which are secured in spaced relation to thebuilding structure proper. Such structures are of course generally knownbut difiiculty has been experienced in providing such structures with asimple, convenient means which will secure the facing slabs in suchrelationship to the structure and in a manner as will permit ready andaccurate assembly, and simple and easy removal and replacement of anyindividual slab without in any way disturbing the remainder.

It is a principal object of the invention to provide a structure andarrangement which overcomes these difficulties and accomplishes theseaims. More explicitly, a principal object is to provide such a structureand arrangement comprised of a few simple parts, which may be easilyfabricated, assembled and used; and which secure the facing slabs inposition without the use of mortar, grout or the like.

A further object of the invention is to provide such a structure andarrangement in which the mounted and assembled facing slabs present anouter surface which is unbroken, fiat and uninterrupted, with no elementor part of the securing means protruding.

A still further object is the provision of securing means in such astructure which, through use of a simple tool such as a screw driver,can be manipulated so as to permit the removal from the front, of anyone facing slab without disturbing the securing effect of the securingmeans for the adjacently disposed facing slabs.

The invention has for a further object the provision of securing means,the parts of which may be made of metal capable of being extruded inlengths before cutting to size, thus permitting manufacture in largequantities at a low production cost.

Still a further object resides in providing securing means which duringassembly of the structure can be simply and readily adjusted, both in avertical and horizontal direction, so as to permit accurate positioningand assembling of the facing slabs on the structure, with proper spacingof the slabs to compensate for expansion and contraction of the slabs aswill occur under varying weather conditions.

Another object of the invention resides in the provision of a specialsecuring means which, while not attached to the building structureproper, will effectively but removably secure the upper edge of eachfacing slab to the bottom edge of the adjacent facing slab immediatelyabove it.

These and other objects of the invention will be more apparent from thefollowing detailed description and claims when read in conjunction withthe accompanying drawings, in which:

FIGURE 1 is a front elevational view of a building facing embodying theinvention;

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FIGURE 2 is an exploded perspective view of one of the bracket hangers,forming a part of the invention;

FIGURE 3 is a vertical section taken through the structure at thelocation of one of the bracket hangers;

FIGURE 4 is a top plan view of one of the bracket hangers in operativeposition;

FIGURE 5 is a perspective view of one of the drive members forming apart of the invention;

FIGURE 6 is a partial front elevational view showing the operativeposition of a drive member, and

FIGURE 7 is a vertical cross section showing a drive member in operativeposition.

The invention will now be described in detail as used, for example, insecuring square or rectangular facings of marble or the like to abuilding structure of precast concrete or the like. Since the inventionhas particular merit in connection with crypts provided with marblefacings, such a form will be described as preferred. In such structuresthe facings are usually disposed in contiguous relationship inhorizontal and vertical rows as illustrated in FIGURE 1 in which thefacing is comprised of the rectangular marble slabs 10. These usuallyare about three feet long and two feet wide and about an inch inthickness. Normally the edges of these facing slabs 10 are spaced aboutan eighth of an inch apart. The ideal arrangement for a crypt is toprovide an arrangement for securing the facing slabs in suchrelationship to each other and spaced slightly from the buildingstructure proper. Moreover, the arrangement should be such that any onefacing slab may be individually removed simply to permit entry to thecrypt, or to permit repair or replacement of the slab. Still further, inaccordance with the invention no part of any of the securing meansshould extend or protrude from the outer or exposed face of the facingslabs, so that at all times an absolutely smooth outer facing isprovided.

The manner in which the invention effects this aim will now bedescribed. The side edges 12 of the facing slabs are flat, but the topedges 14 and bottom edges 16 are such provided with a longitudinalgroove extending the full length of the edge. These grooves are shown inthe cross-sectional views, FIGS. 3 and 7. Their configuration andpurpose will shortly be described in detail. Suffice it to say here thatthe grooves in each. lower edge are formed so to receive the upwardlyflanged portions of bracket hangers 18 which bracket hangers, as will bedescribed, are secured to the vertical wall or other building structuresurface 23 to which the facings are to be applied.

The upper edge of one facing and the lower edge of the next verticallydisposed facing, are slightly spaced when supported by the brackethangers 18. The opposed grooves in these two facing slabs are adapted toreceive specially formed drive members 22 at the corner junction of eachfour contiguous facing slabs, the arrangement being such that one drivemember 22 will, when in fully operative position, engage and secure allfour facing slabs 10 at the corner junction. The general location of thefacing slabs 10, bracket hangers 18 and drive members 22 is shown inFIG. 1. The drive members 22 are secured in position by their engagementwith opposed grooves 24, 26 (FIG. 7) and when in operative position thedrive members 22 thus support the upper edge 14 of each facing slab andprevent the slab from moving forwardly from the building structure. Eachdrive member 22, however, may be moved along in the opposed grooves 24,26, when desired, to a position where it will still support the upperedge of one of the facing slabs 10 but not the next horizontallyadjacent facing slab. When so moved, the upper edge 14 of that facingslab may be swung forwardly from the vertical plane of the remainingfacing slabs and may then be lifted up and out completely to permitrepair or replacement, or access to the crypt building structure itself.

The details of the structure and positioning of the bracket hangers 18will now be described. FIGURE 2 is an exploded perspective view of oneof the bracket hangers 18. Each bracket hanger preferably is comprisedof a metal L-shaped angle member 28 made up of two separate portions 30and 32. The portion 39 is an upright backing portion adapted inoperation to be secured to the building structure 20. For this purposethe backing portion 30 is provided with a vertically disposed elongatedhole 34 adapted to receive a bolt 36 (FIG. 3) which in turn isthreadedly secured in a metal insert 38 (FIG. 3) secured in the buildingstructure 20. The slot and bolt arrangement permits vertical adjustmentof the position of the bracket hanger 18 and thus of the facing slabs10. Extending outwardly from the backing portion 30 at right anglesthereto is a supporting portion 40 which is provided with a slot 42. Theother part of the bracket hanger 18 is a rectangular supporting plate 44having an upstanding flange 46. The supporting plate 44 is provided witha slot 48 which opposingly corresponds to the slot 42 and is alignedtherewith when the supporting plate 44 is secured to the supportingportion 40.

The manner of securing the hanger brackets 18 in place is shown in FIG.3 which is a cross-sectional view. In this figure a portion of the cryptbuilding structure 20 is provided at predetermined locations with themetal inserts 38 each of which has a threaded bore 50 to receive thebolt 36 which passes through the elongated hole 34 in the uprightportion 30 of the bracket hanger 18. The supporting plate 44 is securedto the supporting portion 40 by means of a nut and bolt 52, the boltpassing through the aligned slots 42 and 48. This arrangement permitsthe position of the supporting plate 44 to be adjusted so that theupstanding flange 46 on the supporting plate 44 will be in properposition to engage in the groove 26 in the lower edge 16 of the facingslab 10 and thus to space the facing slab the proper distance from thebuilding structure 20.

The groove 26 in the lower edge of each facing slab is disposedintermediate the front and rear faces of the facing slab. As seen inFIG. 3 the groove 24 extends upwardly in the facing slab 10 a distanceequal to the height of the flange 46 and the groove has a side edge 54and an upper edge 56 corresponding to one side 58 and top edge 68 of theflange 46. Inwardly from the edge 60 of the groove 26 the facing slab iscut away to provide a bevelled surface 62 and a flat surface 64 which isparallel to the bottom edge of the facing slab and spaced upwardlytherefrom a distance equal to the thickness of the supporting plate 44.It will be seen that in operative position the fiat surface 64 rests onand is supported by the supporting plate 44 while the flange 46 isengaged in the groove 26 also supporting the facing slab and normallypreventing it from lateral movement toward and away from the plane offacing slabs. Preferably the lower edge 16 of each facing slab will besupported by two such bracket hangers 18 as generally shown in FIG. 1.

The drive members 22 and the manner in which they support the upperedges 14 of the facing slabs in vertical position while still permittingsimple removal of a facing slab will now be described, reference beinghad to FIGS. 1, and 7. In FIG. 5, which is a perspective view of one ofthe drive members 22, it will be noted that the drive member is formedof a fiat rectangle of a piece of metal of about one-eighth inch inthickness and bent over upon itself to give it a C-shaped cross section,the free ends 66, 68 of the member being parallel to each other and thenextending laterally at right angles to form the flanges 70 and 72.Preferably, the drive member 22 is made of spring metal so that underpressure the flanges will be forced outwardly to forceably engage theopposing grooves 24, 26 in the facing slabs as shown in cross section inFIG. 7. With reference now to FIG. 7 it will be noted that theconfiguration of the groove 26 in the top edge 14 of the lower facing10a is identically complementary to that of the groove 24 in the bottomedge 16 of the upper facing slab 10b shown, one of which grooves havingalready been described in connection with FIG. 3. With further referenceto FIG. 7 it can be seen that the upper and lower surfaces of drivemember 22 are in abutting relationship with the edge 16 of upper slab10b and the edge 14 of lower slab 19a, respectively, at a locationbetween the grooves 24 and 26, respectively, and the left hand edges ofthe slabs as viewed. As best seen in FIG. 5 and FIG. 7, drive member 22extends rearwardly from the grooves 24, 26 to a point beyond the rear orleft hand face of the slabs 10a, 10b. The length of the member 22 in thedirection of the grooves 24, 26 is approximately twice the distance themember 22 projects rearwardly from flanges 70, 72 thereon.

During installation of the facing slabs, one of such metal drive member22 is inserted in the grooves of the four facing slabs at the cornerjuncture of all four as illustrated in FIG. 6 and also in FIG. 1. Insuch position, with its flanges 70 and 72 thrusting into the grooves 24,26, the drive members 22 securely hold the facing slabs together inposition and prevent the top edge 14 of each lower facing slab frommoving out of the plane of the facing slabs.

When, for any reason it is necessary to remove one of the facing slabs,that slab may be removed simply by inserting a screw driver or the likein the space 74 between the slabs and push the drive member 22 along inthe grooves until it is beyond the edge of the facing slab. Thus, inFIG. 6, if it be desired to remove the lower right facing 10 the tool isinserted in the space 74 at the point of arrow A and the drive member 22is pushed and moved to the left in the grooves to a point indicated bythe arrow B. The drive member 22 at the right upper corner of the facingslab (not shown in FIG. 6, but shown in FIG. 1) is similarly moved alongthe grooves, but to the right. The upper edge 14 of the facing slab isthus free and unsecured and may be tilted forwardly out of the plane ofthe facing slabs, pivoting about the edge of the flange 46. (FIG. 3) ofthe bracket hanger 18. It Will be noted that such pivoting isfacilitated by the bevel surface 62 adjacent the groove 24 (FIG. 3). Thefacing may then be lifted out without in any way disturbing the adjacentfacing slabs.

It should now be apparent that the bracket hangers 18 and drive members22 employed permit quick and accurate assembly of the facing slabs. Eachbracket hanger is readily adjustable to permit proper positioning bothvertically and horizontally during actual assembly of the facing slabswhich thus can be properly aligned and spaced in the correct plane.This, on the bracket hangers is accomplished by loosening the bolts andnuts, moving the parts to the desired position, and re-tightening. As tothe drive members 22, they simply need be inserted in the opposedgrooves 24, 26 and then moved into securing position.

All of these securing parts are of simple design. They may be made ofany suitable metal and may be casted, extruded, or otherwise formed togive them the shapes illustrated. In many instances a strong,noncorrodable spring metal is preferred. The shapes lend themselvesadmirably to extruding in long lengths whereupon they may be cut toappropriate size. Moreover, the parts may be manufactured of sectionssufiiciently heavy, or having suflicient section modulus to secure tothe face of a structure slabs of any reasonable thickness and weight.The use of the invention obviously therefore is not limited to thesecuring of comparatively thin slabs.

The invention provides an extremely accurate and uniform jointing of thefinished facing. No variation in the width of the joint is permittedwhich is most difficult to accomplish with other systems.

With this invention a true positioning of the slabs is effected so thatthe faces of all slabs are precisely in the same plane with each slabcorner neither projecting nor being recessed with relation to adjacentcorners.

It should be realized, that in addition to the advantages mentioned,this invention avoids the use of springs or the like used in some priorart devices and which are positioned to bear against the rear side ofthe facing slabs. The invention also avoids the necessity for securingrosettes or other such means disposed the corner juncture of four facingslabs, as is common practice.

The invention is not limited to securing marble facing slabs, butobviously can be employed for securing sheets or slabs of glass, plasticmetal, wood or other materials in slab or sheet form, and may be usedfor surfaces other than walls. Not only does it avoid the necessity formortar, grout, or the like, but it permits proper spacings between theslabs so as to compensate for expansion and contraction, provide properdrainage, and ventilation.

Various modifications of the parts and their arrangement may be madewithin the scope of the invention and within the following claims:

We claim:

1. In a building structure having an upright wall and a facing thereoncomprised of ,a plurality of rectangular slabs arranged in adjacenthorizontal and vertical rows, upper and lower edges of said slabs havinglongitudinal grooves extending from end to end, hanger brackets securedto said wall and each having an upstanding flange engaged in the groovein the lower edge of a slab to support the slab in an upright position,and means disposed at the corner junction of four adjacent slabspositioned to engage in the grooves in all four slabs at said junction,said means comprising a substantially rigid member of spring metal andof C-shaped cross section, the legs of said member being parallel andgreater in length than the dist-ancebetween a groove and the rear faceof a slab, the free ends. of the legs of said member having flangesthereon engaged in the opposed grooves of all four of said facing slabsat said corner junction.

2. A building structure, comprising an upright support, a plurality ofrectangular facing slabs disposed in adjoining vertical and horizontalrows, the upper and lower edges of each of said slabs being providedwith longitudinal grooves from end to end, a plurality of hangerbrackets removably secured to said upright support along parallelhorizontal lines spaced from each other a distance substantially equalto the distance between the grooved edges of a slab, said hangerbrackets having a supporting portion extending outwardly from saidupright support and having an upstanding flange engaged in the groove inthe lower edge of a facing slab to support the slab in a verticalposition, there being at least two such hanger brackets for each slab sosupported, said hanger brackets being positioned inwardly from the sideedges of the slab, and a plurality of C-shaped drive members each havingoutwardly extending flanges on the free ends thereof, one of said drivemembers being disposed at a corner junction of four adjoining facingslabs with one of the flanges thereon engaged in the grooves in thelower edges of the two upper horizontally adjacent slabs which meet atsaid corner junction, the other of said flanges on said drive memberbeing engaged in the grooves in the upper edges of the two lowerhorizontally adjacent slabs which meet at said corner junction.

3. A building structure, comprising an upright support, a plurality ofrectangular facing slabs disposed in a rectangular matrix, the upper andlower edges of each of said slabs being provided with longitudinalgrooves from end to end, .a plurality of hanger brackets removablysecured to said upright support along parallel horizontal lines spacedfrom each other a distance substantially equal to the distance betweenthe grooved edges of a slab, said hangerbrjackets having a supportingportion extending outwardly from said upright support and having anupstanding flange engaging the groove in the lower edge of a facing slaband supporting the slab in a vertical position, there being at least twosuch hanger brackets for each slab so supported, said hanger bracketsbeing positioned inwardly from the side edges of the slab, and aplurality of C-shaped drive members each having outwardly extendingflanges on the free ends thereof, one of said drive members beingdisposed at the corner junction of four adjoining facing slabs with oneof the flanges thereon engaged in the grooves in the lower edges of thetwo upper horizontally adjacent slabs which meet at said cornerjunction, the other of said flanges on said drive member being engagedin the grooves in the upper edges of the two lower horizontally adjacentslabs which meet at said corner junction, the closed end of saidC-shaped members extending inwardly in the direction of said uprightsupport, and beyond the rear face of the slabs.

4. A building structure, comprising an upright support, a plurality ofrectangular facing slabs disposed in adjoining vertical and horizontalrows, the upper and lower edges of each of said slabs being providedwith longitudinal grooves from end to end, a plurality of hangerbrackets removably secured to said upright support along parallelhorizontal lines spaced from each other a distance substantially equalto distance between the grooved edges of a slab, said hanger bracketshaving a supporting portion extending outwardly from said uprightsupport and having an upstanding flange engaged in the groove in thelower edge of a facing slab and supporting the slab in a verticalposition, there being at least two such hanger brackets for each slab sosupported and said hanger, brackets being positioned inwardly from theside edges of the slab, and a plurality of C-shaped drive members eachhaving outwardly extending flanges: on the free ends of said drivemembers, one of said drive members being disposed at the corner junctionof four adjoining slabs with one of the flanges thereon engaged in thegrooves in lower edges of the two upper horizontally adjacent slabswhich meet at said corner junction, the other of said flanges on saiddrive member being engaged in the grooves in the upper edges of the twolower horizontally adjacent slabs which meet at said corner junction,the closed end of said C-shaped members extending inwardly in thedirection of said upright support, said C-shaped drive members being ofspring metal biasing the free ends apart, whereby the flanges moresecurely engage in the respective grooves in which they are disposed inthe slabs when the slabs expand and create greater pressure on saiddrive member.

5. A building structure, comprising an upright support, a plurality ofrectangular facing slabs disposed in adjoining vertical and horizontalrows, the upper and lower edges of each of said slabs being providedwith longitudinal grooves from end to end, a plurality of hangerbrackets reinovably secured to said upright support along parallelhorizontal lines spaced from each other a disstance substantially equalto the distance between the grooved edges of a slab, said hangerbrackets having a supporting portion etxending outwardly from saidupright support and having an upstanding flange engaged in the groove inthe lower edge of a facing slab and to support the slab in a verticalposition, there being at least two such hanger brackets for each slab sosupported and said hanger, brackets being positioned inwardly from theside edges of the slab, and a plurality of C-shaped drive members eachhaving parallel legs having outwardly extending flanges on the free endsthereof, one of said drive members being disposed at the corner junctionof four adjoining slabs with one of the flanges thereon engaged in thegrooves in lower edges of the two upper horizontally adjacent slabswhich meet at said corner junction, the other of said flanges on saiddrive member being engaged in the grooves in the upper edges of the twolower horizontally adjacent slabs which meet at said corner junction,the closed end of said C-shaped members extending inwardly in thedirection of said upright support, the area of said grooved edgesrearwardly of the grooves each having a rectangular cut-out equal inthickness to the thickness of a leg of the C-shaped drive member andadapted to receive a leg therein, whereby an unobstructed space ismaintained between vertically adjacent facing slabs equal to the spacebetween the legs of said C-shaped drive member.

6. A building structure, comprising an upright support, a plurality ofrectangular facing slabs disposed in adjoining vertical and horizontalrows, the upper and lower edges of each of said slabs being providedwith longitudinal grooves from end to end, a plurality of hangerbrackets removably secured to said upright supporting along parallelhorizontal lines spaced from each other a distance substantially equalto the distance between the grooved edges of a slab, said hangerbrackets having a supporting portion extending outwardly from saidupright support and having an upstanding flange engaged in the groove inthe lower edge of a facing slab to support the slab in a verticalposition, there being at least two such hanger brackets for each slab sosupported and said hanger brackets being positioned inward-1y from theside edges of the slab, and a plurality of C-shaped drive members eachhaving parallel legs having outwardly extending flanges on the free endsthereof, one of said drive members being disposed at the corner junctionof four adjoining slabs with one of the flanges thereon engaged in thegrooves in lower edges of the two upper horizontally adjacent slabswhich meet at said corner junction, the other of said flanges on saiddrive member being engaged in the grooves in the upper edges of the twolower horizontally adjacent slabs which meet at said corner junction,the closed end of said C-shaped members extending inwardly in thedirection of said upright support and beyond the rear face of the slabs,said C-shaped drive members being of spring metal biasing the free endsapart, whereby the flanges more securely engage in the respectivegrooves in which they are disposed in the structure when the slabsexpand and create greater pressure on said drive member, said hangerbrackets each being comprised of a metal angle portion having a firstportion secured to the upright support, an integral portion extending atright angles outwardly therefrom, and a separate support plate, thelatter being the portion having said upstanding flange, means foradjustably securing said first portion to the upright support, and meansfor securing the support plate to said integral portion at selecteddistances from said first portion, whereby the position of said brackethangers may be adjusted both vertically and horizontally.

7. A building wall structure comprising an upright wall and facingthereon, said facing comprising vertically disposed slabs havingadjoining edges, each of said slabs being provided with longitudinalgrooves in two of the op-' posite edges thereof wherein a pair ofopposed grooves is formed when a first edge of one slab is in registerwith a second opposite edge of another slab, a securing membercomprising a substantially rigid element including a pair of legs joinedat one end thereof, said member having outwardly extending flangeslocated ,at the other end of said legs engaged in the opposed grooves ofat least one pair of slabs, said legs of said securing member being inabutting relationship with a portion of the edges of said at least onepair of slabs at a location between said longitudinal groove and the endof said edge whereby proper spacing of the slabs is provided as well ascompensation for expansion and contraction.

8. A building wall structure as set forth in claim 7 wherein said rigidelement is comprised of spring metal and said flanges are complementaryin cross section to the cross section of said grooves.

9. A building wall structure as set forth in claim 7 wherein there isincluded at least one means secured to said wall having an upstandingflange engaged in a groove in a lower edge of at least one of said slabsto support the slab in an upright position.

10. A building wall structure as set forth in claim 7 wherein saidsecuring member extends rearwardly from the grooves to a point beyondthe rear face of the slabs, the length of said member in the directionof the grooves being approximately twice the distance said memberprojects rearwardly from the flange portion thereof.

References Cited UNITED STATES PATENTS 2,348,314 5/1944 Spalding 52509 X2,363,156 11/1944 Sinner 52378 2,853,870 9/1958 Sinner 52378 2,860,50411/1958 Sinner 52509 X 2,890,583 6/1959 Grosskortenhaus 52484 X FOREIGNPATENTS 567,364 10/1957 Italy.

FRANK L. ABBOTT, Primary Examiner.

M. O. WARNECKE, Assistant Examiner.

1. IN A BUILDING STRUCTURE HAVING AN UPRIGHT WALL AND A FACING THEREON COMPRISED OF A PLURALITY OF RECTANGULAR SLABS ARRANGED IN ADJACENT HORIZONTAL AND VERTICAL ROWS, UPPER AND LOWER EDGES OF SAID SLABS HAVING LONGITUDINAL GROOVES EXTENDING FROM END TO END, HANGER BRACKETS SECURED TO SAID WALL AND EACH HAVING AN UPSTANDING FLANGE ENGAGED IN THE GROOVE IN THE LOWER EDGE OF A SLAB TO SUPPORT THE SLAB IN AN UPRIGHT POSITION, AND MEANS DISPOSED AT THE CORNER JUNCTION OF FOUR ADJACENT SLABS POSITIONED TO ENGAGE IN THE GROOVES IN ALL FOUR SLABS AT SAID JUNCTION, SAID MEANS COMPRISING A SUBSTANTIALLY RIGID MEMBER OF SPRING METAL AND OF C-SHAPED CROSS SECTION, THE LEGS OF SAID MEMBER BEING PARALLEL AND GREATER IN LENGTH THAN THE DISTANCE BETWEN A GROOVE AND THE REAR FACE OF A 